IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology

1. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
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Volume: 03 Issue: 04 | Apr-2014, Available @ http://www.ijret.org 962
ANALYSIS OF MULTI-HOP RELAY ALGORITHM FOR EFFICIENT
BROADCASTING IN MANETS
Dipali K. Dakhole1
, Archana R. Raut2
1
Computer Science and Engineering Department, G.H. Raisoni College of Engineering, Nagpur, India
2
Computer Science and Engineering Department, G.H. Raisoni College of Engineering, Nagpur, India
Abstract
Broadcasting means communicating information from one to all or many to all nodes in a network. It is widely used in many MANET
routing protocols. Flexible and distributed MANETs are robust and rapidly deployable/reconfigurable, so they are highly appealing
for a lot critical applications, like deep space communication, disaster relief, battlefield communication, outdoor mining, etc. To
improve such limitation for a more efficient utilization of limited wireless bandwidth, this paper proposes a more general probing
based multi-hop relay algorithm with limited energy consumption. A general theoretical framework is further developed to help us to
understand that under different network size, how we can benefit from multiple observations in terms of per node PDR, the expected
end to end delay and limited energy consumption.
Keywords: MANETs, Broadcasting, Multi-hop relay, end-to-end delay, PDR, etc.
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1. INTRODUCTION
In mobile ad hoc networks (MANETs), as nodes move around
randomly, network topology varies dramatically and there
may not exists an end to end path at any given instant. If point
to point communication is there between the nodes, then
surely MANETs gives better throughput. The traditional
routing based protocols such AODV, DSR, etc. fail to function
properly as they require simultaneous availability of number
of links [1] [2]. Two-hop relay algorithm is able to provide a
flexible control of both throughout and packet delay for the
challenging MANETs. But under such routing scheme, a
packet has been transmitted either through direct transmission
from source to destination or by two-hop via an intermediate
relay node, which first receives packet from source and then
forward it to the destination [3],[4]. But here source and
destination must be one relay node apart from each other.
Every node present in MANET can be considered a router.
The source node utilizes the intermediate nodes to transmit the
message towards the destination node if a source node fails to
transmit a message reliably to its destination node. MANET
networks propose reliability, bandwidth and battery power and
have erratic traits like topology, signal strength and
transmission routes. Transmission algorithms and procedures
are supposed to be very light to save energy and bandwidth in
computation and storage necessities. A lot of primary work
has been done to analyze the packet end-to-end delay and
throughput. Regardless of much research activity on the delay
performance study of multi –hop relay MANETs in last
several decades, the important issue of end-to-end delay
modeling in multi-hop relay MANETs remains a technical
challenge. In multi-hop relay MANETs it is also mandatory to
deliver the packet reliably without any loss of data. In multi-
hop relay network system, it is very difficult to choose optimal
path to deliver the data to destination node. Hence sending
node will try for all possible paths, hence it will consume a lot
of energy. To balance the energy constraint is one of the major
challenge in multi-hop relay MANETs.
In this paper, research conducted to address issues in multi-
hop relay selection, delay minimization, energy management
and reliable packet delivery during broadcasting is described.
The paper is organized as follows. Section 2 reviews related
work. Section 3 describes briefly the proposed efficient
technique for broadcasting. Section 4 analyzes the proposed
technique. Section 5 summarizes the paper and point out the
areas of future work.
2. RELATED WORK
A very simple approach for broadcasting is flooding. In this
technique, each node upon receiving a packet for the first time
rebroadcasts it. Such a protocol works well in parse network
and in networks with high mobility, but it is inefficient as
multiple copies will be received by nodes in the network. A lot
of research is done to improve this broadcasting technique [6].
In paper [7], the broadcast based network coding technique
has succeed in improving the packet delay and throughput, but
the results has shown that the actual protocols are still far from
achieving the possible lower bound. A cross session broadcast
technique has been proposed in paper [5]. The results have
shown that this protocol has improved the packet delay, PDR
and throughput as it has divided the network into generations,
however the management of these generations becomes more
complex as their size increases. The last paper studied in

2. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
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Volume: 03 Issue: 04 | Apr-2014, Available @ http://www.ijret.org 963
literature has proposed an algorithm that is applicable for two-
hop relay algorithm [3]. It has improved packet delay and
PDR drastically by considering static network scenario.
To the best of our knowledge, only few papers explicitly
address multi-source wireless broadcast. Also a lot many work
has been done by considering static network scenario only to
get efficient results. Also many papers has focused on delay,
PDR and throughput parameters only, the major constraint
energy parameter is not considered along with these
parameters. Hence more work need to be done to improve
delay, PDR and energy parameters simultaneously.
3. PROPOSED TECHNIQUE
Broadcasting is the act of moving information from source to
all other nodes or from more than one source node to all other
nodes in the network. As we are considering multi-hop relay
network, more than one intermediate node are considered
during transmission of data in terms of packet. The main
purpose of this algorithm is to optimize end-to-end delay,
Packet delivery ratio (PDR) and data transmission energy of
network.
3.1 Definitions
Throughput: As defined in usual way, the average number of
bits that can be transmitted by each node to its destination per
unit time is called as per node throughput. The sum of all per
node throughput over all the nodes in a network is called as the
throughput of the network.
Average Packet Delay: It is the time taken by packet to reach
its destination after it leaves the source. The average packet
delay of a network is obtained by averaging over all
transmitted packets in the network.
Packet Delivery Ratio (PDR): It is the ratio of number of
packets reached successfully at destination to the number of
packets delivered by source node.
Data Transmission Energy: It is the energy of node required
to carry data from source to its destination. The average data
transmission energy of a network is obtained by averaging over
all energy in the network.
3.2 Network Model
For implementation NS2 simulator is used. A network of 50
nodes is considered where all nodes are randomly moving.
Each nodes location is identified by its x and y parameters. In
this scenario every node is numbered from 0 to 49 and
indicated by circles. Nodes 0,1,2,3,4,5 which are in red color
are considered to be broadcasting nodes. The remaining green
colored nodes are data receiving nodes and will act as
intermediate nodes too as shown in Fig.1. The simulation
parameters of the network are given in below table.
Table 1 Simulation Parameters
Queue Capacity 50 packets
Packet Size 1000kB
Packet Interval 0.00001 Sec
Initial Energy of Node 100J
Transmission Power 0.2J
Sleep Power 0.001J
Simulation Area 300 x 300
Simulation Time 10 Sec
Fig 1 Network Formation in Multi-hop Relay MANETs
3.3 Multi-hop Relay Algorithm
As per considered in above network, there are total n (Number
of nodes n =50 ) distinct flows and each node can be a potential
relay for other n-2 flows (excluding the two flows originated
from and destined for itself). To facilitate the operation of the
Multi-hop relay routing protocol, each node is equipped with
three types of First In First Served (FIFS) queues: one source-
queue, one broadcast-queue and n - 2 parallel relay-queues.
These three types of queues are defined as:
Source Queue: It is a local queue storing the locally generated
packets. It stores packets exogenously generated at S and
destined for D. These exogenous packets will be distributed out
to relay nodes later in the FIFS way.
Broadcast Queue: Broadcast-queue stores packets from
source-queue that have already been distributed out by S but
have not been acknowledged yet by D the reception of them.

3. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
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Volume: 03 Issue: 04 | Apr-2014, Available @ http://www.ijret.org 964
Relay Queue: There are n-2 relay queues storing packets from
other n-2 flows (one for each flow).
We denote source node as S and destination node as D as
shown in Fig.2. We have considered a scenario where the
source S and destination D use the push type of service for data
transmission. S periodically sends locally generated packets to
D via multiple intermediate nodes. While designing Multi-hop
Relay algorithm, one problem is that D will receive multiple
copies of packets. Hence to reduce this redundancy, every
receiving intermediate relay node and D node is sending an
acknowledgement ACK to the sending node immediately. Also
to reduce data transmission energy, time allotted to send packet
is 10% of slot and 90% of time is used to wait to receive ACK.
Hence reliable packet delivery is also achieved.
Every time all queues, Source queue, Broadcast queue and
Relay queues are updated. If packet is lost in between
transmission process, then it is recovered from Relay queue of
sender relay node so as to increase the throughput.
Fig 2 Multi-hop Relay Technique in MANETs
Every time S is selected as broadcasting node, it executes the
following Algorithm 1.
Algorithm 1: Multi-hop Relay Algorithm
1. S checks whether its destination D is in the one-hop
neighborhood;
2. if D is within the one-hop neighborhood of S then
3. S executes Procedure 1;
4. else
5. S randomly selects source-to-relay transmission or
relay-to-destination transmission;
6. if S selects source-to-relay transmission then
7. S executes Procedure 2;
8. else
9. S executes Procedure 3;
10. end if
11. end if
Procedure 1: Source to Destination Transmission
1. S directly sends packet to D within 10% of time slot;
2. S waits for ACK within 90% of time slot;
3. if ACK not received then
4. S resends the packet to D;
5. end if
6. S deletes packet from its source queue;
7. D updates the Broadcast queue;
Procedure 2: Source to Relay Transmission
1. S randomly search for nearby relay node R out of one
hop neighbors;
2. S directly sends packet to R within 10% of time slot;
3. S waits for ACK within 90% of time slot;
4. if ACK not received then
5. S resends the packet to R;
6. end if
7. S deletes packet from its source queue;
8. R updates the Relay queue;
Procedure 3: Relay to Destination Transmission
1. R search for destination node D;
2. R directly sends packet to D within 10% of time slot;
3. R waits for ACK within 90% of time slot;
4. if ACK not received then
5. S resends the packet to D;
6. end if
7. R deletes packet from its source queue;
This Multi-hop Relay algorithm has optimized delay
performance, packet delivery ratio and data transmission
energy of network in highly mobile multi-hop relay MANET.
The further section will explain the results obtained in terms of
delay, PDR and energy graph.
4. SIMULATION RESULTS
To validate the above proposed technique on expected end to
end delay, PDR and energy remained after the execution of
simulation, the following graphs are obtained.
4.1 End-to-End Delay Validation
The delay of network is calculated by following formula:
Delay of network = ∑ (Packet arrival time-sent time) / number
of connections.
A graph is plotted as delay of network against number of
nodes. The nodes are varied from 10 to 100 and according to
that the delay of network is plotted for existing 2HR routing
technique and Multi-hop relay technique. The following graph
shows that the proposed Multi-hop relay algorithm has
optimized delay upto 72.79%.

4. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
__________________________________________________________________________________________
Volume: 03 Issue: 04 | Apr-2014, Available @ http://www.ijret.org 965
Fig 3 Delay Vs No of Nodes Graph. Compared 2HR routing
algorithm with proposed Multi-hop Relay Algorithm
4.2 Energy Parameter Validation
Fig 4 Energy Remained in J Vs No of Nodes Graph. Compared
2HR routing algorithm with proposed Multi-hop Relay
Algorithm
The energy of network remained is calculated by following
formula:
Average Energy of network remained = (Max energy-Min
energy) / 2
A graph is plotted as energy of network against number of
nodes. The nodes are varied from 10 to 100 and according to
that the average energy of network is calculated for existing
2HR routing technique and Multi-hop relay technique. The
following graph shows that the proposed Multi-hop relay
algorithm has optimized average energy up to 77%.
4.3 PDR Validation
The energy of network remained is calculated by following
formula:
PDR= Number of packets delivered successfully / Total
number of packets sent
The following graph shows that the packet drop obtained by
2HR Routing algorithm is greater than that of proposed Multi-
hop relay algorithm. The PDR optimized by Multi-hop relay
algorithm is up to 99.90%
Fig 5 Energy Remained in J Vs No of Nodes Graph. Compared
2HR routing algorithm with proposed Multi-hop Relay
Algorithm
Fig 6 Energy Remained in J Vs No of Nodes Graph. Compared
2HR routing algorithm with proposed Multi-hop Relay
Algorithm

5. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
__________________________________________________________________________________________
Volume: 03 Issue: 04 | Apr-2014, Available @ http://www.ijret.org 966
5. CONCLUSIONS
The proposed multi-hop relay algorithm has been implemented
and analyzed by considering delay, PDR and energy consumed
in network. The above results shows that this technique has
been optimized delay by 3.37%, PDR by 1.36% and average
energy of network by 10% than previous techniques in
dynamic network scenario.
Though this technique has improved the broadcasting
efficiency, there is scope to study on link failure mechanism to
improve the technique.
ACKNOWLEDGMENTS
This is my final year ME research project in wireless
communication and computing. I would like to express my
gratitude to Ms. A. R. Raut who guided me throughout the
work. The research work in this paper was supported by G. H.
Raisoni College of engineering, Nagpur.
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